The present invention pertains to a heat exchanger and more particularly, to a compact heat exchanger that allows the use of less expensive materials and prevents the possibility of flue products condensing in unwanted places within the heat exchanger.
In the past, high efficiency gas furnaces have required a secondary coil to be placed below or beside the primary heat exchanger coil. This requires either additional height or width for the furnace, as well as adding plumbing cost to the furnace.
An object of the present invention is to provide an improved heat exchanger for a gas fired furnace, wherein the deficiencies and disadvantages of prior gas fired furnace designs are obviated.
Another object of the present invention is to provide a compact three pass high efficiency heat exchanger for a gas fired furnace that includes a secondary heat exchanger and wherein about 90%-95% of the energy is removed from the flue products flowing there-through.
Yet another object of the present invention is to provide an improved compact heat exchanger comprising three substantially parallel passes operatively connected to a hot collector box that is in turn operatively connected to the secondary heat exchanger, said three parallel passes constructed and arranged to remove about 70%-75% of the energy from the flue products flowing therethrough. Upon entering the secondary heat exchanger, the flue products will be 500.degree..+-.100.degree. F., well above condensing, and all condensing will take place in the stainless steel secondary heat exchanger, allowing the unit to glean a total of 90-95% of the energy input from the fuel. Other objects and advantages of the present invention will become more apparent hereinafter.